Engineered Pichia pastoris production of fusaruside, a selective immunomodulator

BACKGROUD: Fusaruside is an immunomodulatory fungal sphingolipid which has medical potentials for treating colitis and liver injury, but its poor natural abundance limits its further study. RESULTS: In this study, we described a synthetic biology approach for fusaruside production by engineered Pichia pastoris that was based on polycistronic expression. Two fusaruside biosynthesis genes (Δ3(E)-sd and Δ10(E)-sd), were introduced into P. pastoris to obtain fusaruside producing strain FUS2. To further enhance the yield of fusaruside, three relevant biosynthetic genes (Δ3(E)-sd, Δ10(E)-sd and gcs) were subsequently introduced into P. pastoris to obtain FUS3. All of the biosynthetic genes were successfully co-expressed in FUS2 and FUS3. Compared to that produced by FUS2, fusaruside achieved from FUS3 were slightly increased. In addition, the culture conditions including pH, temperature and methanol concentration were optimized to improve the fusaruside production level. CONCLUSIONS: Here a novel P. pastoris fusaruside production system was developed by introducing the biosynthetic genes linked by 2A peptide gene sequences into a polycistronic expression construct, laying a foundation for further development and application of fusaruside. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12896-019-0532-8) contains supplementary material, which is available to authorized users.